\part*{Afterword}
\addcontentsline{toc}{part}{Afterword}

\section{Questions?}

Do not hesitate to mail any questions to the author: \\
\GTT{<\EMAIL>}.
Do you have any suggestion on new content for to the book?
Please do not hesitate to send any corrections (including grammar (you see how horrible my English is?)), etc.

The author is working on the book a lot, so the page and listing numbers, etc., are changing very rapidly.
Please do not refer to page and listing numbers in your emails to me.
There is a much simpler method: make a screenshot of the page, in a graphics editor underline the place where you see the error,
and send it to me. He'll fix it much faster.
And if you familiar with git and \LaTeX\, you can fix the error right in the source code: 

\href{http://go.yurichev.com/17089}{GitHub}.

Do not worry to bother me while writing me about any petty mistakes you found, even if you are not very confident.
I'm writing for beginners, after all, so beginners' opinions and comments are crucial for my job.
